code: def test_union_duplicates() -> None:
      n_dfs = 10
      df_lazy = pl.DataFrame({}).lazy()
      lazy_dfs = [df_lazy for _ in range(n_dfs)]
  
      result = len(
          re.findall(
              r".*CACHE\[id: .*, count: 9].*",
              pl.concat(lazy_dfs).explain(),
              flags=re.MULTILINE,
          )
      )
      assert result
  
imports: import re
  from datetime import date, datetime
  from tempfile import NamedTemporaryFile
  from typing import Any
  import numpy
  import pytest
  import polars
  from polars.testing import assert_frame_equal
label_desc: Use image node_id 2 for calling a global function with example usage: test_union_duplicates() without return types